经验性治疗社区获得性肺炎中的疗效评价

目的 评价β-内酰胺类抗生素联合大环内酯类与单用氟喹诺酮类治疗社区获得性肺炎的疗效.方法 收集符合纳入及排除标准的2010年1月1日至2011年6月30日期间就诊于浙江大学医学院附属第一医院的社区获得性肺炎临床资料并进行分析.结果 有89例病例纳入本次研究,其中56例接受β-内酰胺类抗生素加大环内酯类,33例单用氟喹诺酮类治疗.两组患者在年龄,性别组成,合并症,入院前抗生素治疗,影响体温药物的应用,体征及部分实验室检查等方面差异均无统计学意义(P＞0.05).在临床疗效评价上,两组在入院后退热时间、住院时长及CRP下降80％时间差异均无统计学意义(P＞0.05),根据PSI进行亚组分析差异亦无统计学意义.结论 β-内酰胺类抗生素联合大环内酯类与单用氟喹诺酮类在治疗轻中度社区获得性肺炎时,二者疗效相当.     

阿齐霉素联合头孢噻肟钠治疗老年社区获得性肺炎

目的探讨阿齐霉素联合头孢噻肟对老年社区获得性肺炎(CAP)的临床效果和安全性。方法84例老年CAP随机分为2组。治疗组42例,给阿齐霉素0.5 g,po,qd,连用3 d,同时给头孢噻肟钠2.0 g,静滴,bid。对照组42例,给头孢噻肟钠2.0 g静滴,bid。2组总疗程14 d。结果治疗组与对照组的总有效率分别为90.5%和73.8%,差异有显著性(P<0.05);治疗组与对照组的细菌总清除率分别为80.0%和78.9%,差异无显著性(P>0.05)。结论阿齐霉素联用头孢噻肟钠治疗老年社区获得性肺炎安全、有效。     

Industrial bioconversion of renewable resources as an alternative to conventional chemistry

There are numerous possibilities for replacing chemical techniques with biotechnological methods based on renewable resources. The potential of biotechnology (products, technologies, metabolic pathways) is for the most part well known. Often the costs are still the problem. Biotechnological advances have the best chances for replacing some fine chemicals. While the raw material costs are less of a consideration here, the environmental benefit is huge, as chemical-technical processes often produce a wide range of undesirable/harmful by-products or waste. In the case of bulk chemicals (<US $1/kg) the product price is affected mainly by raw material costs. As long as fossil raw materials are still relatively inexpensive, alternatives based on renewable resources cannot establish themselves. Residues and waste, which are available even at no cost in some cases, are an exception. The introduction of new technologies for the efficient use of such raw materials is currently being promoted. The utilisation of residual wood, plant parts, waste fat, and crude glycerol, for example, provides great potential. For industrial chemicals (US $2–4/kg), process and recovery costs play a greater role. Here, innovative production technologies and product recovery techniques (e.g. on-line product separation) can increase competitiveness.     

The interrelations of radiologic findings and mechanical ventilation in community acquired pneumonia patients admitted to the intensive care unit: a multicentre retrospective study

Background

Burkholderia cepacia complex (BCC) bacteria are highly virulent, typically multidrug-resistant, opportunistic pathogens in cystic fibrosis (CF) patients and other immunocompromised individuals. B. vietnamiensis is more often susceptible to aminoglycosides than other BCC species, and strains acquire aminoglycoside resistance during chronic CF infection and under tobramycin and azithromycin exposure in vitro, apparently from gain of antimicrobial efflux as determined through pump inhibition. The aims of the present study were to determine if oxidative stress could also induce aminoglycoside resistance and provide further observations in support of a role for antimicrobial efflux in aminoglycoside resistance in B. vietnamiensis.

Findings

Here we identified hydrogen peroxide as an additional aminoglycoside resistance inducing agent in B. vietnamiensis. After antibiotic and hydrogen peroxide exposure, isolates accumulated significantly less [³H] gentamicin than the susceptible isolate from which they were derived. Strains that acquired aminoglycoside resistance during infection and after exposure to tobramycin or azithromycin overexpressed a putative resistance-nodulation-division (RND) transporter gene, amrB. Missense mutations in the repressor of amrB, amrR, were identified in isolates that acquired resistance during infection, and not in those generated in vitro.

Conclusions

These data identify oxidative stress as an inducer of aminoglycoside resistance in B. vietnamiensis and further suggest that active efflux via a RND efflux system impairs aminoglycoside accumulation in clinical B. vietnamiensis strains that have acquired aminoglycoside resistance, and in those exposed to tobramycin and azithromycin, but not hydrogen peroxide, in vitro. Furthermore, the repressor AmrR is likely just one regulator of the putative AmrAB-OprM efflux system in B. vietnamiensis.     

Value of rapid aetiological diagnosis in optimization of antimicrobial treatment in bacterial community acquired pneumonia

In 80 adult patients with community acquired pneumonia (CAP) conventional microbiological methods, polymerase chain reaction (PCR) and serum C-reactive protein (CRP) levels were performed and the appropriateness of the empirical antimicrobial treatment was evaluated according to bacterial pathogen detected. The aetiology was determined in 42 (52.5%) patients, with Streptococcus pneumoniae as the most common pathogen. PCR applied to bronchoalveolar lavage (BAL) provided 2 and PCR on sputum samples 1 additional aetiological diagnosis of CAP The mean CRP values in the S. pneumoniae group were not significantly higher than in the group with other aetiological diagnoses (166.89 mg/L vs. 160.11 mg/L, p = 0.457). In 23.8% (10/42) of patients with determined aetiology, the empirical antimicrobial treatment was inappropriate. PCR tests need further investigation, particularly those for the atypical pathogens, as they are predominant in inappropriately treated patients. Our results do not support the use of CRP as a rapid test to guide the antimicrobial treatment in patients with CAP.     

血清降钙素原在婴幼儿社区获得性肺炎诊断中的应用价值

目的探讨血清降钙素原(PCT)在婴幼儿社区获得性肺炎(CAP)鉴别诊断中的应用价值。方法选取2012年10月至2014年10月确诊的158例CAP婴幼儿患者(108例细菌性CAP和50例支原体性CAP)及120例健康婴幼儿进行血清PCT检测和血液白细胞(WBC)检测,比较婴幼儿PCT和WBC的水平,并确定其最佳阈值在细菌性CAP和支原体性CAP鉴别诊断中的应用价值。结果细菌性CAP组和支原体性CAP组中PCT和WBC的水平均显著高于正常对照组(P0.05)。并且PCT在细菌性CAP组显著高于支原体性CAP组(P0.05),在最佳阈值(PCT 4.3 ng/m L,WBC 14.3×109/L)下,PCT对细菌性CAP诊断的敏感性为87.3%,特异性为87.5%,阳性预测值为95.4%,阴性预测值为70.0%,均显著高于WBC。结论血清PCT可有效鉴别细菌性CAP和支原体性CAP,为临床诊断和个性化治疗提供依据。     

Evaluation of the micronucleus test using a Chinese hamster cell line as an alternative to the conventional in vitro chromosomal aberration test.

The in vitro micronucleus (MN) test was carried out simultaneously with the conventional chromosomal aberration (CA) test on 11 clastogenic chemicals or spindle poisons with different modes of action using a Chinese hamster cell line (CHL). The method of slide preparation for the MN test was the same as that for the conventional metaphase analysis, except that 1% acetic acid in methanol was used as the cell suspension medium for air-drying (to preserve the cytoplasm around the nucleus). All chemicals tested induced micronuclei reproducibly and dose-dependently in good agreement with the results of metaphase analysis (r = 0.99). Since the MN test methodology is simple and the observation of MN is less subjective than that of CA, we conclude that the in vitro MN test would be a good alternative to the conventional CA test for screening the genotoxicity of chemicals.     

In vitro embryo production in the cow: an effective alternative to the conventional embryo production approach

Development of new technology related to in vitro embryo production has allowed for the commercial use of this method of reproduction. In the present work, we evaluate the efficiency of this technology compared with conventional embryo production based on results obtained with a standard procedure, including the sexing of embryos. The donor animals were mature nonlactating dairy cows (n = 92) kept under a constant environment and feeding program in an ET center. Ultrasound guided transvaginal ovum pick-up following 48 h pre-treatment with FSH has been used for the IVF-IVC protocol. A total of 437 oocyte recovery sessions performed on 92 cows yielded 4145 oocytes, which were used in an IVF-IVC protocol. Using the conventional approach, 156 embryo collections on 49 cows yielded 1652 ova and embryos. All Quality 1 and 2 embryos were sexed by a PCR procedure, and embryos of the desired sex were transferred to synchronized recipients located at the center. The results obtained in the IVF protocol showed that 4 oocyte collections per cow performed within 60 d, yielded 38 oocytes, which resulted in 18.8 viable embryos, of which 7.05 were female. After transfer of the female embryos, an average of 3.8 recipients were pregnant at 60 d. One embryo collection under the conventional approach yielded an average of 1.2 female pregnancies, which was confirmed during the same 60-d time period. These results indicate that IVF procedures can effectively replace conventional embryo production methods when a predetermined number of pregnancies of known sex are needed within a short period of time.     

Fast neutron treatment as an alternative to radical surgery for malignant tumours of the facial area.

Thirty one patients with very advanced tumours of the maxillary sinus were treated with fast neutrons. Tumour regressed completely in 29 (94%) and subsequently recurred in four (14%). No surgical excision of bone, skin, or nerve was required, and an artificial eye was well tolerated in cases where the eye received the tumour dose and had to be removed. Complications occurred in 10 patients, two of whom had already received radical x ray treatment. The overall duration of neutron treatment was four weeks, and admission to hospital was usually unnecessary. These results compared well with those obtained with surgery. Surgery with curative intent for even moderately advanced tumours of the facial region, particularly the paranasal sinuses, results in deformity, which is often severe and always irreversible. Even so, the cure rate is only about 35%. The high rates of tumour control and the avoidance of severe cosmetic and functional defects after fast neutron treatment make it an alternative to radical surgery in the management of malignant tumours of the facial area.     

Assessment of valve implantation in the descending aorta as an alternative for aortic regurgitation patients not treatable with conventional procedures

Background:

Aortic Regurgitation (AR) produces the entrance of an abnormal amount of blood in the left ventricle. This disease is responsible for high morbidity and mortality worldwide and may be caused by an aortic valve dysfunction. Surgical and transcatheter aortic valve replacement (TAVR) are the current options for treating AR. They have replaced older procedures such as Hufnagel’s one. However, some physicians have reconsidered this procedure as a less aggressive alternative for patients not eligible for surgical or TAVR. Although Hufnagel suggested a 75% regurgitation reduction when a valve is placed in the descending aorta, a quantification of this value has not been reported.

Methods:

In this paper, CFD/FSI numerical simulation is conducted on an idealized geometry. We quantify the effect of placing a bileaflet mechanical heart valve in the descending aorta on a moderate-severe AR case. A three-element Windkessel model is employed to prescribe pressure outlet boundary conditions. We calculate the resulting flow rates and pressures at the aorta and first-generation vessels. Moreover, we evaluate several indices to assess the improvement due to the valve introduction.

Results and conclusions:

Regurgitation fraction (RF) is reduced from 37.5% (without valve) to 18.0% (with valve) in a single cardiac cycle. This reduction clearly shows the remarkable efficacy of the rescued technique. It will further ameliorate the left ventricle function in the long-term. Moreover, the calculations show that the implantation in that location introduces fewer incompatibilities’ risks than a conventional one. The proposed methodology can be extended to any particular conditions (pressure waveforms/geometry) and is designed to assess usual clinical parameters employed by physicians.

     

The bacteriocins of ruminal bacteria and their potential as an alternative to antibiotics

Beef cattle have been fed ionophores and other antibiotics for more than 20 years to decrease ruminal fermentation losses (e.g methane and ammonia) and increase feed efficiency, and these improvements have been explained by an inhibition of gram-positive ruminal bacteria. Ionophores are not used to treat human disease, but there has been an increased perception that antibiotics should not be used as feed additives. Some bacteria produce small peptides (bacteriocins) that inhibit gram-positive bacteria. In vitro experiments indicated that the bacteriocin, nisin, and the ionophore, monensin, had similar effects on ruminal fermentation. However, preliminary results indicated that mixed ruminal bacteria degraded nisin, and the ruminal bacterium, Streptococcus bovis, became highly nisin-resistant. A variety of ruminal bacteria produce bacteriocins, and bacteriocin production has, in some cases, been correlated with changes in ruminal ecology. Some ruminal bacteriocins are as potent as nisin in vitro, and resistance can be circumvented. Based on these results, ruminal bacteriocins may provide an alternative to antibiotics in cattle rations.     

Characteristics of the haemoproteid community in an expanding white-winged dove population

The haemoproteid community of 171 eastern white-winged doves (Zenaida asiatica asiatica) from the expanding Texas population was examined using thin blood smears. During summer 1997, heart blood was taken from doves within their historical breeding range (Lower Rio Grande Valley of Texas), an intermediate region (San Antonio and surrounding area), and the new breeding periphery (north central to southeast Texas). Two species were found: Haemoproteus columbae and Haemoproteus sacharovi. Infracommunities rarely occurred in heart blood, as only 20 of 132 infected doves demonstrated gametocytes of both species. Overall prevalence of H. columbae and H. sacharovi was 77 and 15%, respectively. Prevalence of H. columbae was higher in the Lower Rio Grande Valley (LRGV) and intermediate regions than at the periphery, higher in adults than juveniles, and similar between males and females. Prevalence of H. sacharovi was lower in the LRGV than intermediate and peripheral regions, similar between juveniles and adults, and higher in females than males. Mean density of H. columbae and H. sacharovi was 15.9 +/- 2.7 and 0.3 +/- 0.1 (mean +/- SE per 3,000 erythrocytes), respectively. Overall mean abundance of H. columbae and H. sacharovi was 12.2 +/- 2.2 and 0.04 +/- 0.02, respectively. Mean abundance of H. columbae was higher in the LRGV and intermediate regions than at the periphery and was similar between host age and between host sex; H. sacharovi was similar among regions, host age, and host sex. This study emphasizes the importance of using prevalence, density, and abundance data to assess haemoproteid community structure and pattern.